Revision of the oligosaccharide structures of yeast carboxypeptidase Y.

The N-linked oligosaccharides from baker's yeast carboxypeptidase Y were analyzed by 1H NMR and specific mannosidase digestion and found to be identical to those from the Saccharomyces cerevisiae mnn9 mutant bulk mannoprotein. The results support the view that the mnn mutants make oligosaccharides that are a true reflection of the normal biosynthetic pathway and confirm that a recently revised yeast oligosaccharide structure is applicable to wild-type mannoproteins.